Bittorent Project Wiki
Welcome to the BitTorrent Project The BitTorrent Project is a wiki site that sets forth the main strengths, weaknesses, applications, and challenges facing bit torrent peer-to-peer file sharing. What is BitTorrent? BitTorrent is an open source peer-to-peer file sharing protocol used for the distribution of large amounts of data on the internet. There are essentially two main advantages to using BitTorrent protocol. First, BitTorrent is that it allows massive distribution of popular files without penalizing the source by soaring bandwidth costs and possible crashes due to demand that exceeds the capability of the server. In other words, BitTorrent allows users to receive large amounts of data without putting the level of strain on their computers that accompanies standard internet hosing. Second, and on a related note, BitTorrent allows its users to distribute data more quickly and efficiently than "normal" downloading. Both of these advantages are derrived from the way BitTorrent protocol works. How does BitTorrent Work? (The Theory) "Normal" Downloading Before discussing how BitTorrnet works, let's first examine how "normal" downloading works. Websites reside on servers. Servers "serve up" information to their clients. Your personal computer is a client of these servers as you surf the internet. So, if you come upon a website and click on a link to download a program, you create a one-on-one connection to that server that uses whatever bandwidth is necessary to serve you the file. When you have received the entire file, the connection is released so the server can utilize that stream of bandwidth for handling other connections. There are a couple of problems with this system. First, when an unusually high number of clients visit a site simultaneously, the server can run out of available bandwith, causing a crash. Second, this is a slow, inefficient system. Every client that comes to the table looking for the desired file can only access this file via the single one-on-one connection with the server. Meanwhile, as other clients are downloading the file, they too have access to the file. Therefore, there are many other potential sources for the file out there. In other words, normal downloading ignores these other potential sources and focuses only on the one-on-one connection between individual client and server. A More Inclusive Scheme of Networking Recognizing the burdens and inefficiencies of normal downloading, BitTorrent offers a solution by way of a more inclusive networking scheme. Instead of ignoring the other clients downloading a file as potential alternate sources for that file, it essentially uses them to act as servers to one another. So, a client that is in the process of downloading a file (peer) or a client that has already finished downloading the file (seed) will simultaneously upload the parts of the file received to the other clients downloading the file. So, when you click on a file to download, instead of the one-on-one server-to-client connection that is provided for through normal downloads, several connections will be made to the other clients downloading the same file. In other words, instead of downloading a file from a central server, you are actually downloading different parts of the file from various peers and seeds simultaneously. This alternate networking scheme solves the problems of normal downloading with respect to inefficiencies as well as burdens placed on single sources of files. Since you can download different parts of your file from multiple sources simultaneously, you can download the files much more efficiently and much more quickly. In fact, the more clients that participate, the more potential sources for your file. Therefore, the more clients that participate, the faster your downloads will be. Additionally, since the various clients no longer rely on a single source for the file, the burden is no longer being borne by some hapless server. Instead, the bandwidth burden is being shared between the various clients, reducing the risk of crashing a server. Conclusion BitTorrent's networking scheme leads to a viral distribution of files between peers. As more peers and seeds join the swarm, the speed and likelihood of a successful download increases. When compared to standard Internet hosting, this networking scheme significantly reduces the hardware and bandwidth costs of the original distributor of the file. It also provides redundancy against system problems and therefore reduces the problems of server crashes. How to Use BitTorrent There are basically three steps to using BitTorrent: #Get a BitTorrent Client #Find a Torrent #Download the File Getting a BitTorrent Client A BitTorrent Client is the program that allows you to connect with peer clients and manages uploads and downloads. Several of the most popular are BitLord, BitComet, Vuze, BiTtornado, µTorrent, or the original BitTorrent. Simply following one of the preceeding links, download the client, and install it on your system. In terms of a recommendation, µTorrent is very highly regarded by Windows users. It's a free download and also happens to be extremely small (making it a quick download) and fast. It has a clean, uncluttered interface, but tosses in a few features for more advance users, too. Finding a Torrent and Downloading the File Before we discuss finding and downloading Torrents, it is important to note that a torrent file is not actually the file that you are ultimately downloading. It is merely a pointer to where the file can actually be downloaded. It directs you to the seeds and peers that either already have or are in the process of downloading the file. For example, if you are attempting to download a certain linux distribution or an album by an indie artist, the torrent file associated with these files is not the file itself. Instead, it is the file that will allow you to participate along with the seeds peers in the download swarm. At any rate, on to finding and downloading Torrents. There are a few ways to find torrents. They can be found rather easily through search engines and sites which are called "tracker sites". We will discuss legal issues involving tracker sites a bit later. However, tracker sites essentially index different torrents, making them easier to find. Once you find a torrent file associated with the file that you are actually looking for, you will open the torrent with your BitTorrent Client. This is the moment that you will finally be shown to the file that you are seeking. Once you open the torrent with the BitTorrent Client, you will be shown to the download swarm with the various seeds and peers. At this point, you simply download the files using your BitTorrent Client. Limitations of BitTorrent Leeches As has been discussed, the speed and efficiency of BitTorrent downloads are owed to the swarm of peers and seeds which essentially act as servers to one another. Therefore, this speed and efficiency is dependent on the number of participants who are willing to share the burden and act as a server. The problem arises when users leave the swarm as soon as they have finished downloading the file. If a user does this, that represents one less person participating in the swarm. If enough people do this, swarms can die out altogether. When this happens, any advantage to using BitTorrent is lost. To combat this problem, many BitTorrent websites monitor the upload/download ratio of its users. If a particular user's ratio is particularly heavy on the download side, the site will restrict the speed of that users downloads until he or she uploads more data. Category:Browse